Ensure type-safety with tab audio muting

[petemill]

Fix #14058

Muon will error if receiving a value that is not of the expected type, including undefined.
Optimize which frames are sent from window to browser for muting.

Test plan:

Directly affected by code changes:

• Tab's context-menu: mute all tabs
• Tab Page Indicator context menu: mute all tabs
• Tab Page Indicator context menu: unmute all tabs

Regression tests:

• Tab audio indicator: mute
• Tab audio indicator: unmute

Submitter Checklist:

• Submitted a ticket for my issue if one did not already exist.
• Used Github auto-closing keywords in the commit message.
• Added/updated tests for this change (for new code or code which already has tests).
• Ran git rebase -i to squash commits (if needed).
• Tagged reviewers and labelled the pull request as needed.
• Request a security/privacy review as needed. (Ask a Brave employee to help if you cannot access this document.)

Reviewer Checklist:

• Request a security/privacy review as needed if one was not already requested.

Tests

• Adequate test coverage exists to prevent regressions
• Tests should be independent and work correctly when run individually or as a suite ref
• New files have MPL2 license header

[bsclifton]

Code changes look good- manually tested and it works great 😄 👍

[bsclifton]

master 917c479
0.23.x d9e1f04
0.22.x-release3 e19b5c4